The Battle of Normandy lasted nearly three months – far longer than Allied strategists had anticipated.
The battle to extend the bridgehead was won within ten days and, after a hard-fought struggle, the port of Cherbourg was captured at the end of June, but it was then that all their problems started.
July was the blackest month for the Allies. The British and Canadians were kept at bay north of Caen by German armoured divisions. Only on July 19th was the city entirely liberated. During this time, the Americans made little headway in the Cotentin Peninsula, bogged down in the war of the hedgerows and managing to capture Saint-Lô with only the greatest difficulty on July 18th.
Then, at the end of July, their luck changed. The successful outcome to Operation Cobra allowed the Americans to smash through the enemy defences and sweep southwards into Brittany and towards the Loire.
At the beginning of August, the failure of the Mortain counter-attack, ordered by Hitler, hastened the rout of the German armies, which were now threatened with encirclement. They were partially wiped out in the Falaise Pocket at the end of the month, and those soldiers who escaped were left with no choice but to evacuate the rest of Normandy, cross the Seine and head back to Germany.